US3149468A - Split system master cylinder - Google Patents

Split system master cylinder Download PDF

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Publication number
US3149468A
US3149468A US49765A US4976560A US3149468A US 3149468 A US3149468 A US 3149468A US 49765 A US49765 A US 49765A US 4976560 A US4976560 A US 4976560A US 3149468 A US3149468 A US 3149468A
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US
United States
Prior art keywords
plunger
spring
plungers
retainer
elongated member
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US49765A
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English (en)
Inventor
Paul B Shutt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bendix Corp
Original Assignee
Bendix Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bendix Corp filed Critical Bendix Corp
Priority to US49765A priority Critical patent/US3149468A/en
Priority to GB28629/61A priority patent/GB941340A/en
Priority to DE1961B0046120 priority patent/DE1841741U/de
Priority to FR870666A priority patent/FR1304097A/fr
Priority to DE19611405812 priority patent/DE1405812A1/de
Priority to GB15673/62A priority patent/GB1009391A/en
Priority to SE6316/62A priority patent/SE304183B/xx
Application granted granted Critical
Publication of US3149468A publication Critical patent/US3149468A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T11/00—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant
    • B60T11/10—Transmitting braking action from initiating means to ultimate brake actuator without power assistance or drive or where such assistance or drive is irrelevant transmitting by fluid means, e.g. hydraulic
    • B60T11/16—Master control, e.g. master cylinders
    • B60T11/20—Tandem, side-by-side, or other multiple master cylinder units

Definitions

  • This invention relates to a master cylinder construction and more specifically to a master cylinder having distinct fluid connections to the front set of wheel brakes and the rear set of wheel brakes so that in the event of hydraulic failure of the hydraulic actuating system portion associated with either set of brakes, the other will function.
  • This type of system is sometimes referred to by those skilled in the art as a split hydraulic system and the purpose of these systems is to achieve greater safety in vehicle operation; thus, should there occur a failure in any portion of the hydraulic operating system of the conventional master cylinder, the vehicle is not without effective braking through the hydraulic actuating system.
  • split systems Another obstacle which has precluded adoption of split systems is that the front set of wheel brakes does a greater portion of the braking work that does the rear set of wheel brakes because of greater axle loading on the front axle as compared with the rear axle in the proportion of about 60-40.
  • Split systems which ignore this fact detract from the efliciency of the actuating system and are among the reasons Why split systems have not been adopted in the past.
  • Another object of the invention is to achieve by means of simple, yet effective structure, means for communicating somewhat greater actuating pressure to the front set of wheel brakes than is communicated to the rear set of wheel brakes so that the different fluid pressures communicating to these separate and distinct brakes will be in a constant proportion providing for the different amounts of braking work that each is required to accomplish during the course of a stop.
  • a further object of the invention is to produce a split system master cylinder having all of the advantages cited for split systems in the Way of safety and the like, and yet will not be so intricate in construction or in function as to add prohibitively to the cost of producing, assembling and servicing the system.
  • FIGURE 1 is a section view of the master cylinder taken through the center of the master cylinder and illustrating the components of the master cylinder as they are in retracted or brake released position. Hydraulic 3,149,458 Patented Sept. 22, 1964 "ice line connections to the front set of wheel brakes and the rear set of wheel brakes are shown schematically; and
  • FIGURE 2 is a sectional view taken through the center of a master cylinder constituting a second embodiment of the invention with the components of the master cylinder shown in retracted or brake released position. There is also shown schematically the fluid connections leading to the front set of wheel brakes and the rear set of wheel brakes similar to that shown in FIGURE 1.
  • the master cylinder indicated generally by reference numeral 10 includes a reservoir 12 for containing hy draulic fluid, the reservoir 12 being divided by a partition 14 which separates the hydraulic fluid within the reservoir into two distinct compartments 16 and 13 which are segregated one from the other so that each can contain a full charge of hydraulic fluid although the other has been emptied by a hydraulic failure.
  • the reservoir is defined by four surrounding walls 20, three of said walls being shown, and a cover plate 22 having a sealing gasket suitably secured to the top of the walls 29 to confine the fluid against loss.
  • Each compartment 16, 11: is also provided with a breather opening, opening 34 for compartment 16, and opening 36 for compartment 13 so that fluid can pass freely between cylinder bore 28 and compartment 16, 18 to prevent vacuum formation rearwardly of the pressure-creating faces of plungers 38 and 4d.
  • the plunger 4% is slidably movable through an opening 4-2 in the closure member 44 which closes the open end of the master cylinder bore 28, there being two seals 4-6 to prevent fluid leakage through the opening 42 and across the outer diameter of the closure 44.
  • a snap ring 48 fitted within a slot 59 of the plunger 46 defines the retracted position of the plunger 45
  • a helical spring 52 is compressed between a shoulder 54 formed integrally with the plunger and a collar spring retainer 56 held at the end of the plunger by a snap ring 58.
  • the spring 52 is loaded by whatever preferred amount is indicated from the design of the master cylinder, the only requirement being that the spring 52 be of a spring rate and compressed by a sumcient amount to a predetermined preload, so that both plunger 40 and plunger 38 may be moved in unison.
  • the plunger 38 is biased leftwardly by the caged spring 52 and the plunger 35 is held in engagement with the sleeve 56 to be moved by the plunger 49 through the caged spring 52.
  • the end 61' of the plunger is reduced in diameter and is reciprocable through opening 62 when the plunger 38 reaches its limit of leftward movement, the end of the plunger passing withdn the recess 64.
  • the two plungers 33 and 4t) define two fluid chambers 68 and 7t), the fluid chamber 63 being sealed at one end by seal 72 carried by shoulder 74 and at the other end by seal 76 carried by plunger 38.
  • Chamber at the advance end of 78 of plunger 33 is sealed by a face seal 89 carried by plunger 33 and by a ball seal 82 which closes the end 34 of the master cylinder.
  • In chamber 68 is an outlet port 85 connecting with line 88 having branches 9% and 92 leading to the rear set of wheel brakes 94 and K.
  • the other chamber 76 is similarly provided with an outlet 93 connecting with outlet line having branch lines Hi2 and 134 connecting with the front set of wheel 3 brakes 186, 108.
  • Brakes 94, 96, 186 and 188 are actuated by wheel cylinders and the brake construction and function being well known, forms no part of the present invention.
  • the plungers 38 and 48 are urged retractively by two concentric helical springs 118 and 112 which are compressed against the seats 114 and 116 at one end and against a washer 128 at the other end, the Washer 120 being carried by plunger 38.
  • the springs 110 and 112 act directly upon the plunger 38 urging it retractively and the retractive force of springs 110 and 112 is communicated through plunger 33 and caged spring 52 to the plunger 4-0 causing the plunger 40 to move retractively until snap ring 48 engages closure 44. Since the caged spring 52 is of greater spring preload than the two springs 110 and 112 combined then the two plungers 78 and 49 are fixed retractively at a position defined by engagement of snap ring 58 with the closure 44.
  • the seat or shoulder 114 has a bushing 112 which engages the washer 128 fixing the limit of protractile movement of plunger 38 (movement toward the left in FIG- URE 1) and thereafter, plunger 48 will move relatively to the fixed plunger 38 against the resistance of caged spring 52 the end 60 of the plunger moving slidably through opening 62 through recess 64, there being sufiicient relative movement of the plunger 48 through the recess 64 before bottoming on 66 to provide adequate pressurizing of fluid within chamber 68 to fully apply the rear wheel brakes 94 and 96.
  • the operator In operation, when it is desired to apply the brakes, the operator, through a convenient pedal or the like (not shown) communicates input force to the plunger 40 at its right hand end in FIGURE 1 causing the plunger 48 to move leftwardly and the input force acts through caged spring 52 to impart applying effort on plunger 38, both of the plungers 38 and 40 moving in unison to the left. Since the two plungers 38 and 48 move in unison then the sealing members 72 and 88 cover the compensating ports 30 and 32 simultaneously severing communication of chambers 70 and 68 with compartments 16 and 18 respectively and allowing build-up of pressure in the chambers.
  • the fluid pressure which builds up in chambers 68 and 70 is communicated through outlet lines 86 and 98 through lines 88 and 100 branch lines 90, 92, 182 and 104 to actuate the brakes 94, 96, 186 and 108. Since the caged spring 52 is of a higher preload than the combined rates of springs 110 and 112 the pressure in chamber 70 will be slightly in excess of that in chamber 68 by an amount which equals the differential of the spring rates and the higher pressure in chamber 70 is available to apply the front wheel brakes to a greater extent than the rear wheel brakes which, as explained previously, is desirable because the front wheel brakes do a proportionately greater amount of the work in stopping the vehicle.
  • the master cylinder indicated generally by reference numeral 210 includes a reservoir 212 having a partition 214 which separates the reservoir into two compartments 216 and 218 just as in the previous embodiment.
  • Compensating ports 228 and 222 communicate the respective compartments 216 and 218 with the master cylinder bore 224, there being a breather opening 226 in addition to the compensating port 222 for compartment 218.
  • the master cylinder reservoir is enclosed by walls 228, three of which are shown, and a cover plate 230 having a master cylinder filler cap 232 with the same function described for the filler cap in the previous embodiment.
  • a seal 242 which prevents fluid passage past the seal 242 from variable volume chamber 244.
  • a caged spring 246 which is compressed between two cupshaped stampings 248 and 250 having turned back circular flanges 252 and 254 respectively.
  • stampings 248 and 250 seat against the facing ends of the two plungers 234 and 236 and the amount of energy which is stored in the cage spring can be controlled by simply turning the nut 258 to advance it along the stem 256 or unscrewing it to lengthen the spring 246 and reduce the amount of stored energy therein.
  • the chamber 242 has an outlet 262 leading to the brakes through a residual pressure check valve 264, line 266, branch lines 268 and 270 to the rear wheel brakes at 272 and 274 respectively. Details of the residual pressure check valve are found in Re. 24,664 issued June 30, 1959 Residual Pressure Check Valve.
  • the chamber 244 which communicates with the front wheel brakes is provided with fluid from compartment 216 through compensating port 228 a recess 276 in plunger 236, radial passage 27% and longitudinal passage 280. Communications through the passage 230 from the reservoir compartment 216 is controlled by a valve designated generally by reference numeral 282.
  • the valve 282 has a resilient element 284 carried on the end of a stem 286 by means of a flange 288 which is piloted Within an opening 299 of the plun er 236 and lay-passes notches 291 to permit fluid to flow past the flange 288.
  • abutment 294 At the opposite end of the stem is an abutment 294 which is held normally in engagement with the end 296 of a stepped diameter stamping 298.
  • a coil spring 308 biases the stem 282 rightwardly fixing the spatial location of the sealing element 284 which location is normally out of engagement with 280 so that fluid can pass from the compartment 216 to chamber 244 unimpeded.
  • Fluid pressure from chamber 244 is communicated through a residual pressure check valve 31% to an outlet 312 thence to an outlet line 314 and branch lines 316, 318 connecting with the front set of wheel brakes 32% and 322.
  • the pressure in chamber 244 assisted by spring 392 is balanced against the combination of pressure in chamber 242 and the force of caged spring 246, and since the preload of caged spring is greater than spring 362 the fluid pressure in chamber 244 is greater than that in chamber 242 and thus greater applying force is communicated to the front wheel brakes than is communicated to the rear wheel brakes.
  • the difference in applying pressure effects greater applying force for the front Wheel brakes and this is a desirable condition since the front whee brakes, as previously described, do a greater portion of the braking work in stopping the vehicle.
  • stop means comprises a fixed annular seating member located at the rear of said bore, said first plunger has a flanged portion engaging said annular sealing member.
  • a second retainer is provided which is similar in shape to said first named retainer, the opening of said second retainer receiving said threaded end of said stud therethrough, the annular flange of said second retainer operatively abuts said end surface of said one plunger, said one end of said first coil spring engages said annular flange of said second retainer, whereby said second retainer serves as the operable connection of said stud to said one plunger and said second coil spring additionally serves to engage said one plunger with said annular flange of said second retainer.
  • stop means comprises a fixed annular sealing member located at the rear of said bore, said first plunger has a flanged portion engaging said annular sealing member.

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  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Transmission Of Braking Force In Braking Systems (AREA)
US49765A 1960-08-15 1960-08-15 Split system master cylinder Expired - Lifetime US3149468A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
US49765A US3149468A (en) 1960-08-15 1960-08-15 Split system master cylinder
GB28629/61A GB941340A (en) 1960-08-15 1961-08-08 Master cylinder construction for brakes
DE1961B0046120 DE1841741U (de) 1960-08-15 1961-08-09 Druckzylinder fuer die bremsen von kraftfahrzeugen.
FR870666A FR1304097A (fr) 1960-08-15 1961-08-11 Perfectionnements aux maîtres cylindres
DE19611405812 DE1405812A1 (de) 1960-08-15 1961-08-14 Druckzylinder fuer hydraulische Anlagen zur Betaetigung von Fahrzeugbremsen
GB15673/62A GB1009391A (en) 1960-08-15 1962-04-25 Hydraulic master cylinder device
SE6316/62A SE304183B (cs) 1960-08-15 1962-06-06

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US49765A US3149468A (en) 1960-08-15 1960-08-15 Split system master cylinder
US11540661A 1961-06-07 1961-06-07

Publications (1)

Publication Number Publication Date
US3149468A true US3149468A (en) 1964-09-22

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ID=26727522

Family Applications (1)

Application Number Title Priority Date Filing Date
US49765A Expired - Lifetime US3149468A (en) 1960-08-15 1960-08-15 Split system master cylinder

Country Status (4)

Country Link
US (1) US3149468A (cs)
DE (1) DE1405812A1 (cs)
GB (2) GB941340A (cs)
SE (1) SE304183B (cs)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3210942A (en) * 1960-11-16 1965-10-12 Automotive Prod Co Ltd Hydraulic brake mechanisms
US3232058A (en) * 1962-08-09 1966-02-01 Kelsey Hayes Co Master cylinder
US3292371A (en) * 1962-07-14 1966-12-20 Teves Kg Alfred Master cylinder and brake system incorporating same
US3332240A (en) * 1966-10-18 1967-07-25 Gen Motors Corp Split master brake cylinder
US3513655A (en) * 1968-07-18 1970-05-26 Bendix Corp Spring caging device for master cylinders
US3955371A (en) * 1974-11-18 1976-05-11 Wagner Electric Corporation Anti-cup cutting master cylinder

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3446005A1 (de) * 1984-12-17 1986-06-19 Alfred Teves Gmbh, 6000 Frankfurt Druckzylinder
US4614348A (en) * 1985-10-04 1986-09-30 Aeroquip Corporation Anti-blowout seal
DE3736057A1 (de) * 1987-10-24 1989-05-03 Teves Gmbh Alfred Tandemhauptzylinder fuer hydraulische bremsanlagen von kraftfahrzeugen
DE3905917A1 (de) * 1989-02-25 1990-08-30 Teves Gmbh Alfred Tandemhauptzylinder fuer hydraulische bremsanlagen
US5018353A (en) * 1989-04-03 1991-05-28 General Motors Corporation Center compensating master cylinder
GB2236819B (en) * 1989-09-14 1993-07-14 Gen Motors France Dual master cylinder
DE4018494A1 (de) * 1990-06-09 1991-12-12 Teves Gmbh Alfred Verfahren fuer die einstellung einer kolbenzylinderanordnung
US5303934A (en) * 1991-02-20 1994-04-19 General Electric Company Fluidic actuator scraper seal
US5279125A (en) * 1992-12-08 1994-01-18 Allied-Signal Inc. Master cylinder with caging means to secure return spring limiting stud

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1943886A (en) * 1928-10-29 1934-01-16 Bendix Brake Co Brake apparatus
GB488771A (en) * 1936-07-24 1938-07-13 Rene Lucien Levy Hydraulic transmission applicable, in particular, to the braking of vehicles
US2157733A (en) * 1935-02-07 1939-05-09 Weatherhead Co Brake
US2194816A (en) * 1935-03-21 1940-03-26 Automotive Prod Co Ltd Master cylinder for hydraulic brake systems
US2347239A (en) * 1941-01-03 1944-04-25 Edward H Berno Brake mechanism
GB590897A (en) * 1944-07-19 1947-07-31 Montague William Stokes Improvements in volume compensating devices for hydraulic control systems and the like
FR1045724A (fr) * 1951-05-18 1953-12-01 Maître-cylindre perfectionné pour installation hydraulique de commande

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1943886A (en) * 1928-10-29 1934-01-16 Bendix Brake Co Brake apparatus
US2157733A (en) * 1935-02-07 1939-05-09 Weatherhead Co Brake
US2194816A (en) * 1935-03-21 1940-03-26 Automotive Prod Co Ltd Master cylinder for hydraulic brake systems
GB488771A (en) * 1936-07-24 1938-07-13 Rene Lucien Levy Hydraulic transmission applicable, in particular, to the braking of vehicles
US2347239A (en) * 1941-01-03 1944-04-25 Edward H Berno Brake mechanism
GB590897A (en) * 1944-07-19 1947-07-31 Montague William Stokes Improvements in volume compensating devices for hydraulic control systems and the like
FR1045724A (fr) * 1951-05-18 1953-12-01 Maître-cylindre perfectionné pour installation hydraulique de commande

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3210942A (en) * 1960-11-16 1965-10-12 Automotive Prod Co Ltd Hydraulic brake mechanisms
US3292371A (en) * 1962-07-14 1966-12-20 Teves Kg Alfred Master cylinder and brake system incorporating same
US3232058A (en) * 1962-08-09 1966-02-01 Kelsey Hayes Co Master cylinder
US3332240A (en) * 1966-10-18 1967-07-25 Gen Motors Corp Split master brake cylinder
US3513655A (en) * 1968-07-18 1970-05-26 Bendix Corp Spring caging device for master cylinders
US3955371A (en) * 1974-11-18 1976-05-11 Wagner Electric Corporation Anti-cup cutting master cylinder

Also Published As

Publication number Publication date
GB1009391A (en) 1965-11-10
DE1405812A1 (de) 1968-10-03
GB941340A (en) 1963-11-06
SE304183B (cs) 1968-09-16

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